The present application relates to a nozzle head which has a nozzle support rotatable about an axis driveable by a return flow of the pressure water exiting the nozzles, a brake for braking the rotary movement of the nozzle support, and a stationary housing provided with a pressure connection.
Such a nozzle head is disclosed in the patent application, Ser. No. 335,943. In this drill head a stationary sleeve extends from the pressure water connection and guides the pressure water. The sleeve is arranged in a central passage of a hollow shaft rotatably supported in the housing and connected with the nozzle support. The sleeve extends in an opening of the hollow shaft which expands in diameter relative to a central passage. A labyrinth gap seal is provided between the sleeve and a limiting surface of the expanding opening, has a plurality of ring grooves arranged in the sleeve and expanding the ring gap at one end.
The thusly designed nozzle head can operate with high working pressures and used for removing rust, removing varnish and also for removing concrete to a depth of several centimeters. The nozzle head can be adjusted to such a working pressure which makes unnecessary a sand for a surface cleaning. The cleaning works with pressure water under high working pressures lead to a considerable noise generation and to moistening of the surrounding area of the nozzle head with contaminated water.